"puH Duj qoDDaq bIHtaH ngaQHa'moHwI'meywIj'e'!"
Translation:My keys are inside the car!
Why would it be that? I mean there's nothing wrong with that word, but there's also nothing wrong with the word in the presented sentence. Are you looking for ways to add more suffixes (since this sentence already has an unusual number of suffixes, why not go for max)?
Yes, exactly! Following a word with a lot of suffixes like this in a live conversation can be quite chellenging. Fortunately, the brain begins to save lumps and is able to access a lump rather than having to process every detail. For instance your brain may begin to associate ngaQHa'moHwI' as key rather than as "thing which causes to be un-locked". The bIHtaH primes your brain to be ready for the -'e' and ignore it. In such a case, your brain really only has to deal with two suffixes, -mey and -wIj. Keep practicing! It gets easier.